The cicatrisation of wounds or related damage on different types of tissue generally depends on the proliferation of new epithelial, endothelial and connective tissue. It thus involves a series of co-ordinated cellular and molecular events. It may be retarded or modified by metabolic disruptions that accompany certain protracted diseases, such as venous insufficiency, arteritis, diabetes and even certain therapies.
Angiogenesis, the formation of new blood vessels from the pre-existing vascular network, is essential for the growth of any tissue. It takes place, inter alia, in damaged tissue during its cicatrisation. It is well known that disruption of angiogenesis is associated with the development of many diseases involving a deregulation of vascularisation. Many bibliographical data show, for example, a close link between the appearance of ulcers and the inhibition of angiogenesis in the case of diabetics. Furthermore, it is well documented that the endothelial cells constituting the blood vessels of the peripheral circulation are one of the many targets of damage induced by hyperglycaemia (diabetic microangiopathy). The pharmaceutical market currently offers many topical preparations recommended for the cicatrisation of wounds. In point of fact, their action results from the complementary nature of the various products of which they are composed and which gives them, to a certain extent, their cicatrising property. They protect wounds from the surrounding medium by means of an antiseptic dressing. They stimulate the development of vascularisation and regulate epidermisation. These topical forms consist mainly of a lipid mixture (lanolin, petroleum jelly, glycerol, etc.) to which are added acids (salicylic acid, benzoic acid or malic acid), minerals (zinc oxide or titanium oxide) or halides (starch iodide).
Certain preparations also contain collagen, fibrinogen, serum enzymatic proteolysate (supply of amino acids) or alternatively vitamins (vitamin A) or hormones (4-chlorotestosterone acetate).
A pomade also exists (Madecasol® tulgras from Laboratoires Syntex), the cicatrising action of which is provided by the addition of a mixture of three triterpenes extracted from roots of the plant Centella asiatica (TCEA).
These compounds exert their property by stimulating the biosynthesis of collagen and of glycosaminoglycans. However, these extracts may also give rise to contact allergies in patients.
It is known that one of the complications of diabetes lies in the appearance of skin complaints, such as ulcers (or even ulcerous necrotic angiodermatitis) or perforating dermatitis, which conventional medicaments used for the treatment of diabetes do not manage to control or treat.